1. Field of the Invention
The present invention relates to a platinum temperature sensor, and more particularly, it relates to a platinum temperature sensor employing a platinum resistance thermometer.
2. Description of the Prior Art
Platinum, being chemically stable and having high temperature dependency of electrical resistance, is applied as a material for a temperature sensor. In a conventional platinum temperature sensor, a platinum wire is spirally wound on an insulator, or a platinum resistance pattern is formed as a thick or thin film on a single plate-type alumina substrate, as shown in U.S. Pat. Nos. 4,028,657, 4,050,052 or 3,781,749.
However, the winding type platinum temperature sensor is high in cost and cannot be sufficiently reduced in size, and high resistance values cannot be attained. In the platinum temperature sensor employing a single alumina substrate, on the other hand, the size must be increased in order to attain a high resistance value, while a high resistance value cannot be attained if the size is reduced.
U.S. Pat. No. 3,781,749 discloses a platinum temperature sensor which is obtained by stacking platinum patterns which are formed in a linear straight manner on each layer. However, this sensor has problems similar to those of the aforementioned conventional platinum temperature sensors since sufficient pattern length cannot be attained in each layer.